Huge Study Reveals the Secret of Keeping Lost Weight Off

In the past, studies of weight-control diets that are high in protein
or low in glycemic index have reached varied conclusions, probably
owing to the fact that the studies had insufficient power.

Because of this, a team of researchers enrolled overweight adults
from eight European countries who had lost at least 8% of their initial
body weight with a low-calorie diet. Participants were randomly
assigned, in a two-by-two factorial design, to one of five diets to
prevent weight regain over a 26-week period. These were: a low-protein
and low-glycemic-index diet, a low-protein and high-glycemic-index diet;
a high-protein and low-glycemic-index diet; a high-protein and
high-glycemic-index diet; or a control diet.

A total of 1209 adults were screened (mean age, 41 years, of whom 938
entered the low-calorie-diet phase of the study). A total of 773
participants who completed that phase were randomly assigned to one of
the five maintenance diets; 548 completed the intervention (71%).

Significantly fewer participants in the high-protein and the
low-glycemic-index groups than in the low-protein-high-glycemic-index
group dropped out of the study (26.4% and 25.6%, respectively, vs.
37.4%; P=0.02 and P=0.01 for the respective comparisons). The mean
initial weight loss with the low-calorie diet was 11.0 kg (over 24
pounds).

In the analysis of participants who completed the study, only the
low-protein-high-glycemic-index diet was associated with subsequent
significant weight regain (1.67 kg; 95% confidence interval [CI], 0.48
to 2.87). In an intention-to-treat analysis, the weight regain was 0.93
kg less (95% CI, 0.31 to 1.55) in the groups assigned to a high-protein
diet than in those assigned to a low-protein diet (P=0.003) and 0.95 kg
less (95% CI, 0.33 to 1.57) in the groups assigned to a
low-glycemic-index diet than in those assigned to a high-glycemic-index
diet (P=0.003). The analysis involving participants who completed the
intervention produced similar results. The groups did not differ
significantly with respect to diet-related adverse events.

The investigators in this large European study conclude that a
modest increase in protein content and a modest reduction in the
glycemic index led to an improvement in study completion and maintenance
of weight loss.

Psychotherapist, author and guided imagery pioneer Belleruth Naparstek is the creator of the popular Health Journeys guided imagery audio series. Her latest book on imagery and posttraumatic stress, Invisible Heroes: Survivors of Trauma and How They Heal (Bantam Dell), won the Spirituality & Health Top 50 Books Award